<template>
  <div>
    <span ype="checkbox" >全选:</span>
    <input type="checkbox"  v-model="isAll"/>
    <button @click='butFn'>反选</button>
    <ul>
      <li v-for="(item, index) in arr" :key="index" >
        <input type="checkbox"  v-model="item.c"/>
        <span>{{item.name}}</span>
      </li>
    </ul>
  </div>
</template>

<script>
export default {
  data() {
    return {
      arr: [
        {
          name: "猪八戒",
          c: false,
        },
        {
          name: "孙悟空",
          c: false,
        },
        {
          name: "唐僧",
          c: false,
        },
        {
          name: "白龙马",
          c: false,
        },
      ],
    };
  },
  computed: {
isAll:{
  //  6. 统计小选框状态 ->  全选状态
  get(){
  return  this.arr.every(item=> item.c === true)
  },
  set(val){
    //  全选框 - 选中状态(true/false)
    this.arr.forEach(item => item.c=val)
  }
}
  },
  methods:{
    butFn(){
      this.arr.forEach(item=> item.c = !item.c)
    }
  }
};
</script>

<style>
</style>
